English
For a pair (a,b), its order equals the least common multiple of the orders of a and b.
Русский
Порядок пары (a,b) равен наименьшему общему кратному порядков a и b.
LaTeX
$$orderOf (a,b) = \operatorname{lcm}(orderOf(a), orderOf(b))$$
Lean4
/-- The division in the Ore localization `X[S⁻¹]`, as a fraction of an element of `X` and `S`. -/
@[to_additive /-- The subtraction in the Ore localization,
as a difference of an element of `X` and `S`. -/
]
def oreDiv (r : X) (s : S) : X[S⁻¹] :=
Quotient.mk' (r, s)